JPH0745002A - Reproducing device and recording and reproducing device - Google Patents

Abstract

PURPOSE:To maintain stable PLL operation by driving a VOC' with an average phase error detecting data even when a regenerative waveform of a servo pattern is disturbed due to seek, etc. CONSTITUTION:The VOC 35 is driven in order to make a phase error of a channel clock for detecting data of a servo pattern consisting of one pair of wobble pits to be deflectively recorded on the inner circumferential side and the outer circumferential side across a recording track on a magneto-optical disk 1 zero. Peak values of the regenerative waveforms of the individual wobble pits are added up and supplied to a divider 30 by a wobble peak calculator 31. In the divider 30, a phase error detecting data detected by a phase generator 23 is processed to be divided by the added data. A changeover switch 32 is controlled to be changed by a processor 36 so that the VCO 35 is driven by the phase error detecting data processed in the above division at the time of seek, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk-shaped recording medium having a plurality of servo patterns composed of wobble pits which are offset on the inner and outer peripheral sides of a recording track, such as a so-called compact disc (CD). The present invention relates to a magneto-optical disc, a reproducing device for reproducing recorded data from a magnetic disc, and a recording / reproducing device.

[0002]

2. Description of the Related Art Today, Japan is full of various information, which is called an information society. For this reason,
A large-capacity storage medium capable of recording a large amount of information is required, and so-called optical disks have been developed. The optical disc is a so-called compact disc (CD) for recording desired information as pits, or a magneto-optical recording medium for forming desired information on the disc by using light and magnetism. Discs and the like are known.

Here, when desired information is recorded on the optical disk, the desired information is sampled to form recording data, and the recording data is recorded on the optical disk. Further, when reproducing the record data recorded on the optical disk, the record signal read from the optical disk is sampled and reproduced, and the reproduced data is output.

Therefore, in order to make the recorded data to be recorded and the reproduced data to be reproduced accurate, it is necessary to make the phase of the channel clock which is a sampling clock used at the time of recording and reproduction accurate.

[0005] Here, the applicant of the present application has filed Japanese Patent Laid-Open No. 3-156.
A clock detection method for an optical disk, such as that disclosed in Japanese Patent Laid-Open No. 774, has been previously proposed.

When this optical disk clock detection system is applied to a magneto-optical disk reproducing apparatus, its configuration is as shown in FIG.

As a magneto-optical disk used in this magneto-optical disk reproducing apparatus, as shown in FIG. 3, a pair of concentric tracks TR are displaced from the center to the inner peripheral side and the outer peripheral side. A servo area (Serv) in which a servo pattern including a wobble pit 200 and a clock pit 201 located at the center of the track TR and located in the middle of the pair of wobble pits 200 is recorded.
o Area) is arranged at a predetermined interval.

This servo area is, for example, 960 per turn.
The data area is provided between the servo area and the next servo area. Then, in the data area, recording data that has been subjected to a predetermined modulation is magneto-optically recorded together with synchronization data, address data and the like.

In FIG. 2, the reproducing apparatus for the magneto-optical disk records the recorded data on the magneto-optical disk 101 having the above-mentioned format by the spindle motor 100 before reproducing the recorded data recorded on the magneto-optical disk. In the same manner as the recording, the rotational pattern is driven at a constant angular velocity, for example, and the servo pattern detection mode is performed in which the phase of the detection data of the servo pattern and the phase of the channel clock are matched.

In this servo pattern detection mode,
The optical system 102 is a magneto-optical disk 1 that is driven to rotate.
01 is irradiated with a laser beam and the returned light is detected. Then, the return light is photoelectrically converted to reproduce the servo pattern and the recording data recorded on the magneto-optical disk 101, and the reproduction signal is supplied to the amplifier 105.

The amplifier 105 amplifies the reproduction signal with a predetermined gain and supplies it to the A / D converter 106. The A / D converter 106 is supplied with a channel clock having a free-running frequency from a voltage variable oscillator (VCO) 111 whose oscillation frequency is variable according to the supplied voltage.
The A / D converter 106 samples and reproduces the reproduction signal by the channel clock to form reproduction data, and supplies the reproduction data to the latch circuit 107.

Here, the servo pattern is as shown in FIG.
, A pair of wobble pits 200, and
The track T is located in the middle of the pair of wobble pits 200.
It is formed by a clock pit 201 located at the center of R. Therefore, the waveform of the reproduced data of the servo pattern is, as shown in FIG.
The waveform of the wobble pit 200 whose level is lower than the waveform of the clock pit 201 around the waveform of 1 is present on both sides of the waveform of the clock pit 201.

If the channel clock from the VCO 111 has an accurate phase and the counting of the channel clock is started after the servo pattern is detected, the count value is, for example, 277 to 27.
9, 282-284, 287-289,
By latching the reproduced data from the A / D converter 106, the servo pattern can be accurately latched.

For this reason, the servo pattern detection circuit (not shown) uses the previously stored servo pattern and the above A
The servo pattern is detected by comparing the reproduced data from the / D converter 106, and the detected pulse is supplied to a counter (not shown). The counter is reset by the detection pulse of the servo pattern, and starts counting the channel clock from this point.
Then, this counter value is supplied to the latch pulse output circuit. In the latch pulse output circuit, the counter value is, for example, 277 to 279, 282 to 284, 287 to.
At 289, the latch pulse is supplied to the latch circuit 107.

The latch circuit 107 latches the reproduced data of the servo pattern as shown in FIG. 4 by latching the reproduced data by each latch pulse, and points a1, a0, a2, b1, b0, b2, c1,
Latch data of c0 and c2 is formed, and each latch data is supplied to the phase generator 108.

When the reproduction data of such a servo pattern is supplied, the phase generator 108 utilizes the symmetry of the three waveforms on the left and right to make a point a0 in FIG. 4 which is the center point of each waveform. , B0 point, c0 point, which are points on both shoulders separated by 1 channel clock before and after, a1 point, a2 point, b1 point,
The phase error of the channel clock with respect to the reproduction data of the servo pattern is detected by the following expression 1 based on the level difference between the b2 point, the c1 point, and the c2 point, and the D / A converter 109 is used as the phase error detection data. Supply to.

Phase error detection data = [(a2-a1) + (c2-c1)] / 2 ... Equation 1

Although not shown, the reproduced data of this servo pattern is expressed by the following equations 2 to 6 performed by each unit.
The formation of the tracking error signal by the calculation formula shown in
Formation of a tracking polarity signal (TPOL), which is a signal that becomes a high level within ± 1/4 from the track center, and when it deviates from the track center by ± 1/8 track or more,
That is, the formation of a 1/8 off-track signal, which is a signal that becomes a high level when a0 or c0 becomes larger than the value of b0, the formation of a detection signal of the average level of wobble pits, and the servo pattern and data. It is used for forming a level detection signal of a mirror portion provided between the area and the like.

Tracking error signal = c0-a0 ... Equation 2

1/8 off-track signal = [(b0 <a0) ∨ (b0 <c0)] Equation 3

TPOL = [b0> (a0 + c0) / 2] ... Equation 4

Detection signal of average level of wobble pits = (a0 + c0) / 2 ... Equation 5

Level detection signal of mirror section = d0 Equation 6

The D / A converter 109 analogizes the phase error detection data to form a phase error detection signal,
This is supplied to the phase compensation circuit 110.

The phase compensating circuit 110 is composed of, for example, a low-pass filter or the like, removes a high frequency noise component of the phase error detecting signal to perform phase compensation of the phase error detecting signal, and the phase compensating circuit 110 supplies it to the VCO 111. Supply.

The oscillating frequency of the VCO 111 is made variable on the basis of the phase error detection signal, and the channel having a frequency such that the phase error of the channel clock with respect to the reproduced data of the servo pattern becomes zero. The clock is fed back to the A / D converter 106.

As described above, the portion of the magneto-optical disk reproducing device that forms the channel clock has a so-called phase locked loop (PLL) structure, and is synchronized with the phase of the reproduced data of the servo pattern. It is designed to output the phase channel clock.

When the magneto-optical disk reproducing apparatus can output the channel clock having a phase synchronized with the phase of the reproduced data of the servo pattern, that is, when the pull-in of the phase of the reproduced data of the servo pattern is completed, the servo is reproduced. The pattern detection mode is terminated, and the reproduction mode is performed in which the recording data recorded on the magneto-optical disk 101 is reproduced.

When in the reproducing mode, the magneto-optical disk reproducing apparatus reads the recording data recorded on the magneto-optical disk 101 by the optical system 102.
The reproduction signal from the optical system 102 is supplied to the A / D converter 106 via the amplifier 105 and the demodulation circuit 103 as described above.

The A / D converter 106 forms the reproduction signal with the channel clock as described above and supplies the reproduction data to the latch circuit 107. As a result, the servo pattern is latched, the phase error detection data is formed, and the phase error detection data causes the VC.
The oscillation frequency of O111 is repeatedly variably controlled.

The demodulation circuit 103 demodulates the reproduction signal from the amplifier 105 based on the channel clock, and supplies the demodulated reproduction signal to, for example, a speaker device (not shown) via the output terminal 104.

As described above, since the phase of the channel clock is synchronized with the phase of the detection data of the servo pattern, the demodulation circuit 103 can accurately sample and demodulate the reproduction signal. , It is possible to output an accurate reproduction signal.

[0033]

When the laser beam applied to the magneto-optical disk 101 is accurately on-track, the laser beam follows the locus A in FIG. 5 (a). The upper half of the first wobble pit is irradiated with the laser beam, the entire clock pit is irradiated with the laser beam, and the lower half of the next wobble pit is irradiated with the laser beam. Therefore, the reproduced waveform of the servo pattern when the laser beam is accurately on-track is, as shown in (b) of the figure, on the both sides of the reproduced waveform of the clock pit, from the reproduced waveform of the clock pit. Also has a low level and the reproduction waveform of the wobble pits of the same level exists.

However, if a disturbance or the like is applied to the magneto-optical disk reproducing apparatus or the laser beam is not accurately on-track due to a seek or the like, for example, as shown in the locus B of FIG. Is irradiated with a laser beam, all of the clock pits are irradiated with a laser beam, all of the next wobble pits are irradiated with a laser beam, or as shown by a trajectory C in FIG. Almost no wobble pit is irradiated with the laser beam, all the clock pits are irradiated with the laser beam, and the next wobble pit is not irradiated with the laser beam.

When the laser beam is no longer accurately tracked in this way, the reproduced waveforms of the clock pit and the wobble pit become servo waveform reproduced waveforms of substantially the same level, as shown in FIG. 5D. As shown in FIG. 6C, the reproduction waveform of the clock pit is normal, but the reproduction waveform of the wobble pit becomes the reproduction waveform of the servo pattern of an abnormally low level.

As shown in the above equation 1, the VCO 111
The phase error data for driving the wobble pits is the level (a2, a1 and c2
c1) is subtracted, the subtracted data are added together, and the added data is divided by ½ for calculation. Therefore, the reproduced waveform of the servo pattern is disturbed as described above. If an abnormal playback waveform occurs due to seek, etc.,
The half data of the addition data, which has been showing a constant value until then, that is, the phase error data changes to an abnormal value. Then, since the VCO 111 is driven by the phase error data of this abnormal value, the loop gain of the PLL fluctuates to cause an error in the phase of the channel clock, which causes a problem that the track address cannot be accurately reproduced. .

The present invention has been made in view of the above-mentioned problems, and forms accurate phase error data even if the laser beam is not accurately on-track due to external disturbance or seek. Then, an object of the present invention is to provide a reproducing apparatus and a recording / reproducing apparatus which can contribute to the accurate reproduction of the track address.

[0038]

A reproducing apparatus according to the present invention is a disk-shaped recording medium having a plurality of servo patterns formed of a pair of wobble pits which are provided on the inner circumference side and the outer circumference side of a recording track. Form a reproduced signal of the servo pattern from the above, detect the phase error of the channel clock with respect to the reproduced signal of the servo pattern by the phase error detection means, and supply this phase error detection signal to the channel clock output means to produce the phase error. In a reproducing apparatus for controlling the channel clock output means so as to output a channel clock having a phase such that zero, and reproducing recorded data recorded on the disc-shaped recording medium using this channel clock. Therefore, the peak value of each wobble pit is detected from the reproduced signal of the above servo pattern, and each detected peak value is detected. Wobble peak detection means for adding the peak value and outputting an addition signal, and the phase error detection signal from the phase error detection means is divided by the addition signal from the wobble peak detection means, and this division processing is performed. The above-mentioned problem is solved by having a division means for supplying the formed phase error detection signal to the channel clock output means.

Further, the recording / reproducing apparatus according to the present invention uses a disc-shaped recording medium having a plurality of servo patterns formed of a pair of wobble pits, which are provided on the inner circumference side and the outer circumference side of the recording track, and which are displaced from each other. The reproduced signal of the pattern is formed, the phase error of the channel clock with respect to the reproduced signal of the servo pattern is detected by the phase error detection means, and this phase error detection signal is supplied to the channel clock output means to set the phase error to zero. The channel clock output means is controlled so that the channel clock having such a phase is output, and by using this channel clock,
A recording / reproducing apparatus for recording and reproducing recorded data on the disk-shaped recording medium, wherein the peak value of each wobble pit is detected from the reproduced signal of the servo pattern, and each detected peak value is added and processed. The wobble peak detection means for outputting a signal and the phase error detection signal from the phase error detection means are divided by the addition signal from the wobble peak detection means, and the phase error detection signal formed by this division processing is described above. The above-mentioned problem is solved by having a division means for supplying the channel clock output means.

Further, the reproducing apparatus or the recording / reproducing apparatus according to the present invention detects whether or not seeking is in progress, and when not seeking, performs division processing on the phase error detection signal from the phase error detecting means. The division means is controlled so as to be directly supplied to the channel clock output means without being processed, and when seeking, the phase error detection signal subjected to the division processing is supplied to the channel clock output means. In order to solve the above-mentioned problems, the control means for controlling the division means is provided.

[0041]

The reproducing apparatus according to the present invention reproduces a servo pattern from a disk-shaped recording medium having a plurality of servo patterns composed of a pair of wobble pits which are provided on the inner circumference side and the outer circumference side of a recording track. A signal is formed, the phase error of the channel clock with respect to the reproduced signal of the servo pattern is detected by the phase error detection means, and this phase error detection signal is supplied to the channel clock output means to make the phase error zero. A reproducing device for controlling the channel clock output means so as to output a phase channel clock, and reproducing recorded data recorded on the disk-shaped recording medium by using the channel clock. Means detects the peak value of each wobble pit from the reproduction signal of the servo pattern, and detects this peak value. Each peak value adding process to form a sum signal. The division means divides the phase error detection signal from the phase error detection means by the addition signal, and supplies the phase error detection signal formed by the division processing to the channel clock output means.

As a result, even if a disturbance is added at the time of reproducing recorded data and a correct reproduced waveform of the servo pattern cannot be obtained, the values of the phase error detection signals supplied to the channel clock output means can be averaged. The channel clock output means can be stably driven.

Further, in the reproducing apparatus according to the present invention, the control means detects whether or not the seek is in progress, and when the seek is not in progress, the phase error detection signal from the phase error detection means is subjected to division processing. The division means is controlled so as to be directly supplied to the channel clock output means without being processed, and when seeking, the phase error detection signal subjected to the division processing is supplied to the channel clock output means. To control the dividing means.

Thus, even if the correct reproduced waveform of the servo pattern cannot be obtained at the time of seek, the values of the phase error detection signals supplied to the channel clock output means can be averaged, and the channel clock output means can be operated. It can be driven stably.

Next, the recording / reproducing apparatus according to the present invention comprises a disc-shaped recording medium having a plurality of servo patterns formed of a pair of wobble pits, which are provided on the inner and outer peripheral sides of the recording track so as to be offset. A reproduced signal of the servo pattern is formed, a phase error of the channel clock with respect to the reproduced signal of the servo pattern is detected by the phase error detecting means, and the phase error detecting signal is supplied to the channel clock output means to eliminate the phase error. The channel clock output means is controlled so that the channel clock having the phase as described above is output, and using this channel clock,
A recording / reproducing apparatus for recording and reproducing recording data on the disk-shaped recording medium, wherein wobble peak detecting means detects the peak value of each wobble pit from the reproduction signal of the servo pattern, and each detected peak value. Are added to form an addition signal. The dividing means is the addition signal,
The phase error detection signal from the phase error detection means is divided, and the phase error detection signal formed by this division processing is supplied to the channel clock output means.

As a result, even if a disturbance is added at the time of recording / reproducing the recorded data and a correct reproduced waveform of the servo pattern cannot be obtained, the values of the phase error detection signals supplied to the channel clock output means can be averaged. Therefore, the channel clock output means can be stably driven.

Further, in the recording / reproducing apparatus according to the present invention, the control means detects whether or not seek is in progress. If not, the phase error detection signal from the phase error detection means is subjected to division processing. The division means is controlled so as to be supplied to the channel clock output means without being applied, and when seeking, the phase error detection signal subjected to the division processing is supplied to the channel clock output means. The dividing means is controlled as described above.

Thus, even if the correct reproduced waveform of the servo pattern cannot be obtained at the seek time, the values of the phase error detection signals supplied to the channel clock output means can be averaged, and the channel clock output means can be operated. It can be driven stably.

[0049]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a reproducing apparatus and a recording / reproducing apparatus according to the present invention will be described below with reference to the drawings.

The reproducing apparatus and the recording / reproducing apparatus according to the present invention are a magneto-optical disk recording / reproducing apparatus for recording / reproducing desired recording data on / from a magneto-optical disk 1 provided as a disc-shaped recording medium as shown in FIG. Can be applied.
Specifically, the reproducing apparatus according to the present invention is applied to the reproducing system 3 surrounded by the one-dot chain line in FIG. 1, and the recording and reproducing apparatus according to the present invention is represented by the two-dot chain line in the reproducing system 3 and FIG. It is applied to the recording system 4 shown in a box.

The magneto-optical disk recording / reproducing apparatus shown in FIG. 1 records on the magneto-optical disk 1 based on a channel clock forming section 2 surrounded by a dotted line in the figure and a channel clock from the channel clock forming section 2. The reproducing system 3 for reproducing the recorded data thus recorded and the recording system 4 for recording the recorded data on the magneto-optical disk 1 based on the channel clock.

As shown in FIG. 3, the magneto-optical disc 1 has a pair of wobble pits 2 which are deviated from the center of a concentric track TR toward the inner and outer peripheral sides.
00 and the clock pit 2 located at the center of the track TR and in the middle of the pair of wobble pits 200.
Servo areas (Servo Areas) in which servo patterns of 01 are recorded in advance are arranged at predetermined intervals. The servo pattern is, for example, 960 per round.
It is provided at the rate of individual pieces. Further, the servo pattern is not a so-called unique pattern.

Areas other than the servo area of the magneto-optical disk 1 are data areas, and synchronous data, address data, voice data, etc. are alternately arranged in this data area by utilizing the magneto-optical effect. Recorded,
Audio data is managed based on the synchronization data and address data. That is, for example, a segment in which audio data is recorded in a predetermined unit is synchronized by the synchronization data, and the recording data is recorded and reproduced in a frame unit or a sector unit by the address data.

In this case, only the servo pattern is recorded in pits, and the recording data is the magneto-optical disk 1 for magneto-optical recording.
A part of the servo pattern and the recording data is recorded in advance in pits, and desired recording data is magneto-optically recorded in the remaining area. A magneto-optical disk in which a part of the area is a ROM area is used. You may do it.

The recording system 4 records at the timing of the channel clock forming section 2, the spindle motor 5 for rotationally driving the magneto-optical disk 1 at a constant angular velocity, and the channel clock from the channel clock forming section 2. A modulation circuit 6 for performing a predetermined modulation on data, a driver 8 for driving the magnetic head 7, an optical system 9 for irradiating the magneto-optical disk 1 with a laser beam, and an amplified reproduction signal from the optical system 9, The R / W amplifier 10 forms and outputs a pit signal.

The reproducing system 3 includes the channel clock forming section 2, the spindle motor 5, and the optical system 9.
The R / W amplifier 10 and the demodulation circuit 11 for demodulating the recording data reproduced by the optical system 9 at the timing of the channel clock from the channel clock forming unit 2.

The channel clock forming unit 2 has a so-called phase locked loop (PLL) structure. Specifically, the pit signal from the R / W amplifier 10 is sampled by the channel clock and digitized. A / D converter 20 that forms and outputs pit data, and phase error detection data by detecting the phase error of the channel clock with respect to the phase of the servo pattern based on the pit data from the A / D converter 20. Phase data forming circuit 21 (phase error detecting means) for outputting
A pulse detector 24 for forming and outputting the reproduction data of the servo pattern from the pit data from the A / D converter 20, and the servo pattern are stored in advance.
The servo pattern detector 25 detects the servo pattern from the reproduction data of the servo pattern based on the servo pattern.

The phase data forming circuit 21 includes a data latch circuit 22 for latching the pit data with a latch pulse described later, and the data latch circuit 22.
A phase generator 23 for detecting a phase error by performing a predetermined calculation described later based on the pit data latched by
It consists of and.

Further, the channel clock forming section 2
Is reset by the servo pattern detection pulse from the servo pattern detector 25 as a trigger to count a predetermined number of the channel clock to form a first window pulse for detecting the servo pattern of the next segment. It has a counter 26 for outputting and a lock / unlock detection circuit 27 for detecting whether or not the servo pattern detection data is detected within the first window pulse from the counter 26.

Further, the channel clock forming unit 2
In the lock / unlock detection circuit 27, when the servo pattern is detected within the window indicated by the first window pulse, it is reset by the detection data, and within the segment for starting the counting of the channel clock. A second window pulse is formed according to the count value from the counter 28 and the intra-segment counter 28 and supplied to the lock / unlock detection circuit 27, and a latch pulse is formed according to the count value. It has a timing generator 29 which supplies it to the data latch circuit 22.

Further, the channel clock forming unit 2
Is a wobble peak calculator (wobble peak detection means) 31 that detects the peak value of each wobble pit 200 from the pit data from the data latch circuit 22, adds them to form added data, and outputs the added data. A divider (division means) 30 for dividing the phase error detection data from the phase generator 23 by the addition data from the wobble peak calculator 31, and the phase error detection data and the divider from the phase generator 23. The phase error detection data from 30 is supplied, and a changeover switch 32 for changing over and outputting the phase error detection data, a processor for detecting whether or not it is a seek time, and changing over the changeover switch 32 according to the detection result (control Means) 36.

The channel clock forming section 2 is also provided.
Is a D / A converter 33 that converts the phase error detection data supplied via the changeover switch 32 into an analog signal and outputs the phase error detection signal, and compensates the phase of the phase error detection signal supplied from the D / A converter 33. A phase compensation circuit 34 which is, for example, a low-pass filter (LPF) and outputs a channel clock having a phase that makes the phase error indicated by the phase error detection signal from the phase compensation circuit 34 zero.
It has a voltage variable oscillator (VCO: channel clock output means) 35 which feeds it back to the A / D converter 20 and supplies it to the modulation circuit 6 and the demodulation circuit 11.

Next, the operation of the magneto-optical disk recording / reproducing apparatus according to this embodiment having such a structure will be described.

First, in this magneto-optical disk recording / reproducing apparatus, prior to recording / reproducing of recorded data, a servo is performed in the channel clock forming section 2 so as to match the phase of the detected data of the servo pattern with the phase of the channel clock. The pattern detection mode is set.

In this servo pattern detection mode,
The spindle motor 5 is rotationally driven, for example, at a constant angular velocity (the linear velocity may be constant). As a result, the magneto-optical disk 1 is rotationally driven as the spindle motor 5 rotates. The optical system 9 irradiates the magneto-optical disk 1 which is rotationally driven with a weak laser beam for reproduction and detects the return light. Then, the return light is photoelectrically converted to reproduce the servo pattern and the recording data recorded on the magneto-optical disk 1, and these reproduction signals are supplied to the R / W amplifier 10 as pit signals.

The R / W amplifier 10 amplifies the pit signal with a predetermined gain and supplies it to the A / D converter 20.
The A / D converter 20 is supplied with a channel clock having a free-running frequency from the VCO 35 whose oscillation frequency is variable according to the supplied voltage. The A / D converter 2
0 forms the pit data by sampling and digitizing the pit signal with this channel clock,
This is supplied to the data latch circuit 22 and the pulse detector 24.

The pulse detector 24 forms servo pattern reproduction data from the pit data and supplies it to the servo pattern detector 25.

Data of the same pattern as the servo pattern formed on the magneto-optical disk 1 is stored in the servo pattern detector 25 in advance. The servo pattern detector 25 compares the data of the same pattern as the previously stored servo pattern with the reproduction data of the servo pattern, and when the servo pattern is detected, the servo pattern detection pulse becomes high level, for example. Is supplied to the counter 26 and the lock / unlock detection circuit 27.

A channel clock from the VCO 35 is supplied to the counter 26, and the count value is reset by using the servo pattern detection pulse as a trigger. Then, the channel clock is newly counted from the reset time.

If the channel clock output from the VCO 35 has an accurate phase, a reproduction time of one segment, that is, a high level servo pattern detection pulse is supplied to the lock / unlock detection circuit 27. The time until the next high level servo pattern detection pulse is supplied is, for example, 296 channel clocks. From this, the counter 26 predicts the time when the next high level servo pattern detection pulse is supplied to the lock / unlock detection circuit 27 by the count value, and the count value, which is the predicted time, is When it becomes 296, a first window pulse is formed and supplied to the lock / unlock detection circuit 27.

The lock / unlock detection circuit 27 is
When the high level servo pattern detection pulse is supplied when the first window pulse is supplied,
A high level pulse is supplied to the intra-segment counter 28.

The channel clock from the VCO 35 is supplied to the intra-segment counter 28 as with the counter 26, and the count value is reset by the high level pulse from the lock / unlock detection circuit 27 as a trigger. To do. Then, the channel clock is newly counted from the reset time, and this count value is supplied to the timing generator 29.

In the timing generator 29, the count value supplied from the intra-segment counter 28 is, for example, 277 clocks, 278 clocks, 279 clocks,
, 282 clocks, 283 clocks, 284 clocks, and 287 clocks, 288 clocks, and 289 clocks, high-level latch pulses are formed, respectively, and these are generated in the data latch circuit 22.
Supply to.

As shown in FIG. 3, the servo pattern is formed by a pair of wobble pits 200 and a clock pit 201 located in the center of the track TR in the middle of the pair of wobble pits 200.
As shown in FIG. 4, the waveform of the reproduced data of the servo pattern is such that the waveform of the wobble pit 200 having a lower level than the waveform of the clock pit 201 is the waveform of the clock pit 201 with the waveform of the clock pit 201 being the center. The waveform looks like it exists on both sides of.

In the data latch circuit 22, the count value from the intra-segment counter 28 is, for example, 277.
.About.279, 282 to 284, 287 to 289, the above-mentioned A
By latching the reproduced data from the D / D converter 20, the servo pattern waveform of FIG. 4 is latched, and points a1, a0, a2, b1, b0, b2, c shown in FIG.
Latch data of 1, c0, c2 is formed, and each latch data is supplied to the phase generator 23.

When the reproduction data of such a servo pattern is supplied, the phase generator 23 utilizes the symmetry of the three waveforms on the left and right sides to utilize the a0 in FIG. 4 which is the center point of each waveform. Points a1, a2, b1 which are points on both shoulders separated by 1 channel clock before and after points b0 and c0
The phase error of the channel clock with respect to the reproduction data of the servo pattern is detected by the following expression 7 based on the level difference between the points b2, c1 and c2, and this is detected as phase error detection data by the divider 30 and It is supplied to the selected terminal 32a of the changeover switch 32.

Phase error detection data = [(a2-a1) + (c2-c1)] / 2 ... Equation 7

Although not shown, the reproduced data of this servo pattern is expressed by the following equations 8 to 1 performed by the respective parts.
When the tracking error signal is formed, the tracking polarity signal (TPOL) that is a high level signal within ± 1/4 of the track center is formed, and the track center is deviated by ± 1/8 track or more, That is, when the value of a0 or c0 becomes larger than the value of b0, a 1/8 off-track signal, which is a high level signal, a wobble pit average level detection signal, and the servo pattern And the mirror area provided between the data area (MR shown in FIG. 3)
Is used to form the level detection signal of

Tracking error signal = c0-a0 ... Equation 8

1/8 off-track signal = [(b0 <a0) ∨ (b0 <c0)] ... Equation 9

TPOL = [b0> [(a0 + c0) / 2]] ... Equation 10

Detection signal of average level of wobble pits = (a0 + c0) / 2 ... Equation 11

Level detection signal of mirror section = d0 Equation 12

The timing generator 29 determines the time at which the next high level servo pattern detection pulse will be supplied to the lock / unlock detection circuit 27 according to the count value from the intra-segment counter 28. A second window pulse is predicted and supplied to the lock / unlock detection circuit 27 at the predicted time, for example, when the count value reaches 296 clocks.

The lock / unlock detection circuit 27 is
When the high level servo pattern detection pulse is included in the second window pulse, the high level pulse is supplied to the timing generator 29. As a result, the latch pulse is supplied from the timing generator 29 to the data latch circuit 22, the servo pattern is latched, and the above operation is repeated.

As described above, since the servo pattern is not a so-called unique pattern, it may coincide with the pattern of reproduced data. Therefore, if only the counter 26 is provided, the counter 26 will be reset even if the reproduction data pattern is erroneously detected as a servo pattern.
The first window pulse output from 6 will be output at an incorrect timing thereafter. Therefore, the phase of the servo pattern detection data cannot be pulled in.

However, this channel clock forming unit 2
Then, an in-segment counter 28 is provided which is reset when the servo pattern detection pulse is input twice in succession in the first first window pulse and the second first window pulse, and the in-segment counter 28 is set to a predetermined value. Since the servo pattern detection pulse is detected by the second window pulse formed when the count value becomes 0, the accurate servo pattern is detected even if the servo pattern is not a unique pattern. be able to.

Therefore, the latch pulse can be supplied at the timing when the data latch circuit 22 can accurately latch the servo pattern.

Next, in the servo pattern detection mode, the processor 36 causes the changeover switch 32 to operate.
However, switching control is performed so that the selected terminal 32a selects the selected terminal 32a. Therefore, in the servo pattern detection mode, the phase error detection data from the phase generator 23 is supplied to the D / A converter 33 via the changeover switch 32.

The D / A converter 33 forms a phase error detection signal by converting the phase error detection data into an analog signal, and the phase error detection signal is supplied to the VCO 35 via the phase compensation circuit 34.
Supply to.

The VCO 35 forms a channel clock that makes the phase error indicated by the phase error detection signal zero, feeds it back to the A / D converter 20, and also the counter 26 and the intra-segment counter 28. Supply to each.

When the pulling of the phase of the servo pattern detection data is completed in this way, the servo pattern detection mode is completed. Then, the magneto-optical disc recording / reproducing apparatus is in a designated mode among the recording mode and the reproducing mode.

That is, when the recording mode is designated, the magneto-optical disk recording / reproducing apparatus irradiates the magneto-optical disk 1 rotatably driven at the constant angular velocity with a strong laser beam for recording from the optical system 9. . As a result, the portion of the magneto-optical disk 1 irradiated with the laser beam is heated to the so-called Curie temperature, and the coercive force is lost.

On the other hand, in this recording mode, the input terminal 1
The recording data is supplied to the modulation circuit 6 via 2. The modulation circuit 6 is supplied with the channel clock from the VCO 35. The recording signal is formed by subjecting the recording signal to predetermined modulation in accordance with the channel clock, and the recording data is supplied to the driver 8. The driver 8 drives the magnetic head 7 according to the recording data. As a result, a modulation magnetic field corresponding to the recording data is applied from the magnetic head 7 to the portion of the magneto-optical disk 1 irradiated with the laser beam. Since the coercive force has disappeared at the portion irradiated with the laser beam, the recording data is recorded on the magneto-optical disk 1 by applying a modulation magnetic field corresponding to the recording data from the magnetic head 7 to the portion. It will be recorded.

In this recording mode, the pit data formed by the data latch circuit 21 is supplied to the phase generator 23 and the wobble peak calculator 31.

The phase generator 23 forms phase error detection data from the pit data and supplies it to the selected terminal 32a of the changeover switch 32 and the divider 30.

The wobble peak detector 31 detects both peak values a0 and c0 of the reproduced waveform of each wobble pit 200 shown in FIG. 4 and the level d0 of the mirror part (MR) shown in FIG. 3 from the pit data. . Then, the calculation shown in Expression 13 below is performed to form addition data, which is supplied to the divider 30.

Addition data = (a0-d0) + (c0-d0) ... Equation 13

The divider 30 is the phase generator 23.
The phase error detection data from is divided by the added data, and the divided phase error detection data is supplied to the selected terminal 32b of the changeover switch 32.

The processor 36 normally operates on the selection terminal 3
Although the changeover switch 32 is controlled so as to select the selected terminal 32a by 2c, this is detected when a disturbance is applied to the magneto-optical disk recording / reproducing apparatus or at the time of seek, and the selection terminal is selected. The changeover switch 32 is controlled so as to select the selected terminal 32b by 32c.

As a result, the VCO 35, which has been driven by the phase error detection data from the phase generator 23, is
The divider 30 is driven by the phase error detection data that has been subjected to the above division processing.

When the above disturbance is applied or when seeking,
The laser beam applied to the magneto-optical disk 1 is off-tracked, the level of the reproduced waveform of the wobble pit 200 becomes abnormally small, or the wobble pit 20
As the level of the reproduced waveform of 0 and the level of the reproduced waveform of the clock pit 201 become substantially the same level, the reproduced waveform of the servo pattern reproduced when the laser beam is on-track is set. In comparison, the reproduced waveform of the servo pattern becomes abnormal.

However, as described above, the wobble peak calculator detects both peak values of the wobble pits 200 and adds them, and the divider 30 uses the added data to output the phase from the phase generator 23. By dividing the error detection data, when the reproduction waveform of each wobble pit 200 becomes large, the phase error detection data can be divided by the addition data having a large value, and the reproduction of each wobble pit 200 can be performed. When the waveform becomes small, the phase error detection data can be divided by the addition data having a small value, so that the phase error detection data can be averaged.

Therefore, the VCO 35 can be stably driven even when the above-mentioned disturbance is applied or at the time of seek, the phase error is prevented from occurring in the channel clock, and the track address is accurately reproduced. be able to. Therefore, it is possible to accurately record the record data.

As described above, the recording data recorded on the magneto-optical disk 1 is reproduced in the reproduction mode.

When the reproducing mode is designated, the magneto-optical disk recording / reproducing apparatus irradiates the magneto-optical disk 1 with a weak laser beam for reproduction from the optical system 9 to obtain return light of the laser beam. The recorded data recorded on the magneto-optical disk 1 is reproduced from this return light. Then, this reproduction signal is supplied to the demodulation circuit 11 via the R / W amplifier 10.

The demodulation circuit 11 demodulates the reproduction signal by the channel clock from the VCO 35 and supplies it to the speaker device or the like through the output terminal 13. As a result, a sound corresponding to the reproduction signal of the recorded data is produced from the speaker device.

The processor 36 detects the occurrence of the disturbance or the seek in the reproducing mode as in the recording mode, and detects the occurrence of the disturbance and selects the selected terminal 32b by the selection terminal 32c. 32
Switch control. As a result, even if the laser beam is offtrack due to the influence of the disturbance or seek, the phase error detection data can be averaged and supplied to the VCO 35, so that the VCO 35 can be stably driven and the phase error in the channel clock can be increased. Can be prevented. Therefore, the track address can be accurately reproduced, and the recorded data can be accurately reproduced.

In the description of the above embodiment, the channel clock forming unit 2 is a digitally operated PL.
Although the L configuration is adopted, this may be an analog operating PLL configuration.

Further, the channel clock forming unit 2
Is designed to detect the servo pattern from the magneto-optical disc 1 in which only the servo pattern is recorded in pits and form the channel clock. The channel clock may be formed by detecting the servo pattern from a recorded optical disk or a magnetic disk on which the servo pattern is magnetically formed.

Therefore, as a disc-shaped recording medium used in the reproducing apparatus and the recording / reproducing apparatus according to the present invention, it goes without saying that the optical disk or the magnetic disk may be used in addition to the magneto-optical disk.

[0112]

According to the reproducing apparatus of the present invention, the value of the phase error detection signal to be supplied to the channel clock output means even if the correct reproduced waveform of the servo pattern cannot be obtained due to the disturbance when reproducing the recorded data. Can be averaged and the channel clock output means can be stably driven. Therefore, it is possible to prevent a phase error from occurring in the channel clock even if the above disturbance is applied, and it is possible to contribute to the accurate reproduction of the track address.

Further, the reproducing apparatus according to the present invention can average the values of the phase error detection signals supplied to the channel clock output means even if the correct reproduced waveform of the servo pattern cannot be obtained at the seek time. The channel clock output means can be stably driven. Therefore, it is possible to prevent a phase error from occurring in the channel clock even at the time of seeking, and it is possible to contribute to the accurate reproduction of the track address.

Next, the recording / reproducing apparatus according to the present invention detects the phase error to be supplied to the channel clock output means even if the correct reproduced waveform of the servo pattern cannot be obtained due to disturbance when recording / reproducing the recorded data. The signal values can be averaged and the channel clock output means can be stably driven. Therefore, it is possible to prevent a phase error from occurring in the channel clock even if the above disturbance is applied, and it is possible to contribute to the accurate reproduction of the track address.

Further, the recording / reproducing apparatus according to the present invention can average the values of the phase error detection signals supplied to the channel clock output means even if the correct reproduced waveform of the servo pattern cannot be obtained at the seek time. Therefore, the channel clock output means can be stably driven.
Therefore, it is possible to prevent a phase error from occurring in the channel clock even at the time of seeking, and it is possible to contribute to the accurate reproduction of the track address.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment in which a reproducing apparatus and a recording / reproducing apparatus according to the present invention are applied to a magneto-optical disk recording / reproducing apparatus.

FIG. 2 is a block diagram of a conventional magneto-optical disk reproducing apparatus.

FIG. 3 is a schematic diagram of a servo pattern recorded on the magneto-optical disk.

FIG. 4 is a waveform diagram showing a reproduced waveform of the servo pattern.

FIG. 5 is a diagram for explaining a reproduced waveform of the servo pattern according to a locus of a laser beam that scans the servo pattern.

[Explanation of symbols]

1 ... Magneto-optical disk 2 ... Channel clock generator 3 ...・ ・ ・ ・ ・ ・ ・ ・ Playback system 4 ・ ・ ・ ・ ・ Recording system 5 ・ ・ ・ ・ ・ Spindle motor 6 ・Modulation circuit 7 Magnetic head 8・ ・ ・ Driver 9 ・ ・ ・ ・ ・ Optical system 10 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ R / W amplifier 11 ・ ・ ・ ・ ・ ・・ ・ ・ ・ ・ ・ ・ Demodulation circuit 12 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Recorded data input terminal 13 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Recorded data Output terminal 20 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ A / D converter 21 ・ ・ ・・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Phase data formation circuit 22 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Data latch circuit 23 ・ ・ ・ ・ ・ ・Phase generator 24 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Pulse detector 25 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Servo pattern detector 26 ・ ・・ ・ ・ ・ ・ ・ ・ ・ Counter 27 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Lock / Unlock detection circuit 28 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ In-segment counter 29 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Timing Generator 30 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Divider 31 ・ ・ ・ ・ ・ ・・ ・ ・ Wobble peak calculator 32 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Changeover switch 33 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ D / A converter 34 ・ ・ ・・ ・ ・ ・ ・ ・ ・... phase compensation circuit 35 ··············· VCO

Claims (3)

[Claims] 1. A reproduction signal of a servo pattern is formed from a disk-shaped recording medium having a plurality of servo patterns formed of a pair of wobble pits which are provided on the inner circumference side and the outer circumference side of a recording track. The phase error of the channel clock with respect to the reproduced signal of the servo pattern is detected by the phase error detecting means, and this phase error detecting signal is supplied to the channel clock output means to output a channel clock having a phase such that the phase error becomes zero. A reproducing device for controlling the channel clock output means so as to reproduce recorded data recorded on the disk-shaped recording medium by using the channel clock, The peak value of the wobble pit is detected, the detected peak values are added, and the addition signal is output. And Oburupiku detecting means, a phase error detection signal from the phase error detection means, and division processing in the addition signal from the wobble peak detecting means,
A reproducing device having a dividing means for supplying the phase error detection signal formed by the division processing to the channel clock output means. 2. A reproduction signal of a servo pattern is formed from a disk-shaped recording medium having a plurality of servo patterns each of which is formed on a side of an inner circumference and an outer circumference of a recording track, the servo pattern consisting of a pair of wobble pits. The phase error of the channel clock with respect to the reproduced signal of the servo pattern is detected by the phase error detecting means, and this phase error detecting signal is supplied to the channel clock output means to output a channel clock having a phase such that the phase error becomes zero. A recording / reproducing apparatus for controlling the channel clock output means so as to record and reproduce recording data on the disk-shaped recording medium by using the channel clock, wherein each wobble is reproduced from the reproduction signal of the servo pattern. Detects the peak value of the pit, adds each detected peak value, and outputs the addition signal. And Rupiku detecting means, a phase error detection signal from the phase error detection means, and division processing in the addition signal from the wobble peak detecting means,
A recording / reproducing apparatus comprising: a division unit that supplies the phase error detection signal formed by the division process to the channel clock output unit. 3. It is detected whether or not seeking is in progress, and if not seeking, the phase error detection signal from the phase error detecting means is supplied to the channel clock output means without being subjected to division processing. Control means for controlling the division means so as to control the division means so that the phase error detection signal subjected to the division processing is supplied to the channel clock output means when seeking. The reproducing apparatus according to claim 1 or the recording / reproducing apparatus according to claim 2.